Calyx small, 5-parted. Petals 5. Stamens 5, inserted under the edge or between the lobes of a flattened disk in the bottom of the calyx. Fruit small and indehiscent, a sort of dry drupe.--Leaves usually compound.

Flowers greenish-white or yellowish. (The old Greek and Latin name.)

-- 1. RHUS proper. _Fruit symmetrical, with the styles terminal._

[*] _Flowers polygamous, in a terminal thyrsoid panicle; fruit globular, clothed with acid crimson hairs; stone smooth; leaves odd-pinnate. (Not poisonous.)_--(-- SUMAC, DC.)

1. R. tphina, L. (STAGHORN SUMACH.) _Branches and stalks densely velvety-hairy_; leaflets 11--31, pale beneath, oblong-lanceolate, pointed, serrate, rarely laciniate.--Hillsides. June.--Shrub or tree 10--30 high, with orange-colored wood. Apparently hybridizes with the next.

2. R. glabra, L. (SMOOTH S.) _Smooth, somewhat glaucous_; leaflets 11--31, whitened beneath, lanceolate-oblong, pointed, serrate.--Rocky or barren soil. June, July.--Shrub 2--12 high. A var. has laciniate leaflets.

3. R. copallna, L. (DWARF S.) _Branches and stalks downy; petioles wing-margined_ between the 9--21 oblong or ovate-lanceolate (often entire) leaflets, which are oblique or unequal at the base, smooth and shining above.--Rocky hills. July.--Shrub 1--7 high, with running roots.

[*][*] _Flowers polygamous, in loose and slender axillary panicles; fruit globular, glabrous, whitish or dun-colored; the stone striate; leaves odd-pinnate or 3-foliolate, thin.

(Poisonous.)_--(-- TOXICODENDRON, DC.)

4. R. venenata, DC. (POISON S. or DOGWOOD.) Smooth, or nearly so; _leaflets 7--13, obovate-oblong_, entire.--Swamps. June.--Shrub 6--18 high. The most poisonous species; also called _Poison Elder_.

5. R. Toxicodendron, L. (POISON IVY. POISON OAK.) Climbing by rootlets over rocks, etc., or ascending trees, or sometimes low and erect; _leaflets 3, rhombic-ovate_, mostly pointed, and rather downy beneath, variously notched, sinuate, or cut-lobed,--high-climbing plants (R.

radcans, _L._) having usually more entire leaves.--Thickets, low grounds, etc. June.

[*][*][*] _Flowers polygamo-dicious, in small solitary or cl.u.s.tered spikes or heads which develop in spring before the leaves; leaves 3-foliolate; fruit as in first group. (Not poisonous)._--(-- LOBADIUM, Torr. & Gray.)

6. R. Canadensis, Marsh. Leaves soft-p.u.b.escent when young, becoming glabrate; leaflets rhombic-obovate or ovate, unequally cut-toothed, 1--3' long, the terminal one cuneate at base and sometimes 3-cleft; flowers pale yellow. (R. aromatica, _Ait._)--Dry rocky banks, W. Vt. to Minn., and southward.--A straggling bush, 3--7 high; the crushed leaves not unpleasantly scented.

Var. trilobata, Gray. With smaller leaflets (--1' long), crenately few-lobed or incised toward the summit.--Long Pine, Neb., and common westward. Unpleasantly scented.

-- 2. CTINUS. _Ovary becoming very gibbous in fruit, with the remains of the styles lateral; flowers in loose ample panicles, the pedicels elongating and becoming plumose; leaves simple, entire._

7. R. cotinodes, Nutt. Glabrous or nearly so; leaves thin, oval, 3--6'

long; flowers and fruit as in the cultivated _Smoke-tree_ (R.

Cotinus).--Mo. to Tenn., and southward.--A tree, 25--40 high.

ORDER 31. POLYGALaCEae. (MILKWORT FAMILY.)

_Plants with irregular hypogynous flowers, 4--8 diadelphous or monadelphous stamens, their 1-celled anthers opening at the top by a pore or c.h.i.n.k, the fruit a 2-celled and 2-seeded pod._

1. POLGALA, Tourn. MILKWORT.

Flower very irregular. Calyx persistent, of 5 sepals, of which 3 (the upper and the 2 lower) are small and often greenish, while the two lateral or inner (called _wings_) are much larger, and colored like the petals. Petals 3, hypogynous, connected with each other and with the stamen-tube, the middle (lower) one keel-shaped and often crested on the back. Stamens 6 or 8; their filaments united below into a split sheath, or into 2 sets, cohering more or less with the petals, free above; anthers 1-celled, often cup-shaped, opening by a hole or broad c.h.i.n.k at the apex. Ovary 2-celled, with a single anatropous ovule pendulous in each cell; style prolonged and curved; stigma various. Fruit a small, loculicidal 2-seeded pod, usually rounded and notched at the apex, much flattened contrary to the very narrow part.i.tion. Seeds carunculate.

Embryo large, straight, with flat and broad cotyledons, in scanty alb.u.men.--Bitter plants (low herbs in temperate regions), with simple entire often dotted leaves, and no stipules; sometimes (as in the first two species) bearing cleistogamous flowers next the ground. (An old name composed of p????, _much_, and ???a, _milk_, from a fancied property of its increasing this secretion.)

[*] _Perennial or biennial; flowers purple or white; leaves alternate._

[+] _Flowers showy, rose-purple, conspicuously crested; also bearing inconspicuous colorless cleistogamous flowers on subterranean branches._

1. P. pauciflia, Willd. _Perennial_; flowering stems short (3--4'

high), from long slender prostrate or subterranean shoots, which also bear concealed fertile flowers; lower leaves small and scale-like, scattered, the _upper ovate, petioled, crowded_ at the summit; _flowers 1--3, large_, peduncled; wings obovate, rather shorter than the fringe-crested keel; stamens 6; caruncle of 2 or 3 awl-shaped lobes longer than the seed.--Woods, in light soil, N. Eng. to Minn., Ill., and southward along the Alleghanies. May.--A delicate plant, with very handsome flowers, 9" long, rose-purple, or rarely pure white. Sometimes called _Flowering Wintergreen_, but more appropriately FRINGED POLYGALA.

2. P. polgama, Walt. Stems numerous from the _biennial_ root, mostly simple, ascending, very leafy (6--9' high); _leaves oblanceolate or oblong_; terminal _raceme loosely many-flowered_, the broadly obovate wings longer than the keel; stamens 8; radical flowers racemed on short subterranean runners; lobes of the caruncle 2, scale-like, shorter than the seed.--Dry sandy soil; common. July.

[+][+] _Flowers white, in a solitary close spike; none cleistogamous._

3. P. Senega, L. (SENECA SNAKEROOT.) Stems several from thick and hard knotty rootstocks, simple (6--12' high); leaves lanceolate or oblong-lanceolate, with rough margins; wings round-obovate, concave; crest short; caruncle nearly as long as the seed.--Rocky soil, W. New Eng. to Minn., and southward. May, June.

Var. latiflia, Torr. & Gray. Taller, sometimes branched; leaves ovate or ovate-lanceolate, 2--4' long, tapering to each end.--Md. to Mich. and Ky.

4. P. alba, Nutt. Stems several from a hard rootstock, 1 high; leaves narrowly linear, 3--12" long, acute; wings oblong-obovate; crest small; lobes of the caruncle half the length of the appressed-silky seed.--Neb.

and Kan. to Tex.

[*][*] _Annuals, with all the leaves alternate; flowers in terminal spikes, heads or racemes, purple or rose-color, in summer; none subterranean._

[+] _Keel conspicuously crested; claws of the true petals united into a long and slender cleft tube much surpa.s.sing the wings._

5. P. incarnata, L. Glaucous; stem slender, sparingly branched; leaves minute and linear-awl-shaped; spike cylindrical; flowers flesh-color; caruncle longer than the narrow stalk of the hairy seed.--Dry soil, Penn. to Wisc., Iowa, Neb., and southward; rather rare.

[+][+] _Keel minutely or inconspicuously crested; the true petals not longer but mostly shorter than the wings; seed pear-shaped._

6. P. sanguinea, L. Stem sparingly branched above, leafy to the top; _leaves oblong-linear; heads globular, at length oblong_, very dense (4--5" thick), bright red-purple (rarely paler or even white); pedicels scarcely any; _wings broadly ovate, closely sessile_, longer than the pod; the 2-parted _caruncle almost equalling the seed_.--Sandy and moist ground; common.

7. P. fastigiata, Nutt. Stem slender, at length corymbosely branched; _leaves narrowly linear_, acute, 3--8" long; _spikes short and dense_ (3" in diameter); the small rose-purple flowers on _pedicels of about the length of the pod_; wings obovate- or oval-oblong, narrowed at the base, scarcely exceeding the pod; _bracts deciduous_ with the flowers or fruits, caruncle as long as and nearly enveloping the stalk-like base of the minutely hairy seed.--Pine barrens of N. J. and Del. to Ky., and southward.

8. P. Nuttallii, Torr. & Gray. Resembles the last, but usually lower; spikes cylindrical, narrow; flowers duller or greenish purple, on very short _pedicels_; the awl-shaped scaly _bracts persistent_ on the axis after the flowers or fruits fall; seed very hairy, the caruncle smaller.--Dry sandy soil, coast of Ma.s.s. to Mo., and southward.--Spike sometimes rather loose.

9. P. Curtissii, Gray. Slender (9' high), leaves, etc., as in the two preceding, flowers rose-purple, in usually short racemes; pedicels about equalling or exceeding the persistent bracts; _the narrow oblong erect wings fully twice the length of the pod_; caruncle small, on one side of the stalk-like base of the very hairy _seed_, which is _conspicuously apiculate at the broader end_.--Md. to Ga.--The species was founded upon an abnormal form with elongated racemes and pedicels.

[*][*][*] _Annuals with at least the lower stem-leaves whorled in fours, sometimes in fives; spikes terminating the stem and branches; fl. summer and autumn._

[+] _Spikes short and thick (4--9" in diameter); bracts persisting after the fall of the (middle-sized) rose or greenish purple flowers; crest small._

10. P. cruciata, L. Stems (3--10' high) almost winged at the angles, with spreading opposite branches; leaves nearly all in fours, linear and somewhat spatulate or oblanceolate; _spikes sessile or nearly so; wings broadly deltoid-ovate, slightly heart-shaped, tapering to a bristly point_ or rarely pointless; caruncle nearly as long as the seed.--Margin of swamps, Maine to Va. and southward near the coast, and west to Minn.

and Neb.

11. P. breviflia, Nutt. Rather slender, branched above; leaves scattered on the branches, narrower; _spikes peduncled; wings lanceolate-ovate, pointless or barely mucronate_.--Margin of sandy bogs, R. I., N. J. and southward.

[+][+] _Spikes slender (about 2" thick), the bracts falling with the flowers, which are small, greenish-white or barely tinged with purple, the crest of the keel larger._

12. P. verticillata, L. Slender (6--10' high), much branched; stem-leaves all whorled, those of the (mostly opposite) branches scattered, linear, acute; spikes peduncled, usually short and dense, acute; wings round, clawed; the 2-lobed caruncle half the length of the seed.--Dry soil; common.

Var. ambigua. Leaves (and branches) all scattered or the lowest in fours; spikes long-peduncled, more slender, the flowers often purplish and scattered. (P. ambigua, _Nutt._)--N. Y. to Mo., and southward.

[*][*][*][*] _Biennials or annuals, with alternate leaves, and yellow flowers, which are disposed to turn greenish in drying; crest small; flowering all summer._

13. P. lutea, L. Low; _flowers (bright orange-yellow) in solitary ovate or oblong heads_ (' thick) terminating the stem or simple branches; leaves (1--2' long) obovate or spatulate; lobes of the _caruncle nearly as long as the seed._--Sandy swamps, N. J. and southward, near the coast.

14. P. ramsa, Ell. _Flowers (citron-yellow) in numerous short and dense spike-like racemes_ collected in a flat-topped _compound cyme_; leaves oblong-linear, the lowest spatulate or obovate; _seeds_ ovoid, minutely hairy, _twice the length of the caruncle_.--Damp pine-barrens, Del. and southward.

15. P. cymsa, Walt. Stem short, naked above, the numerous racemes in a usually nearly simple cyme, leaves narrow, ac.u.minate; seeds globose, without caruncle.--Del. and southward.